This invention relates to an editing device and a data transmission method, and particularly to an editing device and a data transmission method for editing and transmitting digital video signals.
Videos of television broadcasting programs are normally produced by editing material data recorded on a magnetic tape. Editing work may be classified into on-line editing for, carrying out editing by using a high-definition material tape for broadcast, and off-line editing for carrying out rough editing by copying onto an editing tape. For normal editing, off-line editing using no valuable material tape is carried out.
Recently, a digital editing device based on a personal computer has been diffused as an editing device used for editing work. The digital editing device has a storage unit which uses a hard disk or the like for storing video data and enables non-linear access thereto, and a digital picture processing unit. The digital editing device is capable of carrying out editing operation at a timing independent of an external equipment after video data is transferred from a digital video tape recorder (digital VTR) to the hard disk. Since video signals are recorded on the recording medium which enables non-linear access thereto, it is not necessary to edit the video signals along the time series, and video editing may be carried out while the recording medium is randomly accessed. Such editing method is referred to as non-linear editing.
Non-linear editing is a convenient method because it is not necessary to take synchronization with an external video equipment connected to the editing device. However, in the case where edited videos of high definition are needed, it may be better to reproduce videos from a magnetic tape and edit the reproduced videos (linear editing). Therefore, a hybrid editing device which enables non-linear editing and linear editing is demanded.
However, in order to constitute a hybrid editing device, it is necessary to carry out synchronous transfer of video data between an external video equipment, such as, a VTR, connected to the editing device and a hard disk unit in the editing device. Therefore, a data transmission method which enables easy and reliable synchronous control is necessary. In addition, it is desired to carry out the synchronous transfer at a higher speed so as to make the time-consuming editing work quicker and more efficient.
In view of the foregoing status of the art, it is an object of the present invention to provide an editing device and a data transmission method for digital data which enable high-speed data transfer in synchronization with video signals from an external video equipment.
An editing device according to the present invention includes a format converting section for converting input data to internal transfer data, an internal bus to which the data outputted from the format converting section is transferred, and a data transfer control section for performing control to plurally divide a transmission unit having a length equal to a predetermined period prescribed by an analog signal, lay out the input data in each of divided areas, and transfer the transmission unit as the internal transfer data onto the internal bus in synchronization with the input data.
A data transmission method according to the present invention includes a first step of plurally dividing a transmission unit having a length equal to a predetermined period prescribed by an analog signal, a second step of laying out input data in each area divided at the first step and outputting the transmission unit as internal transfer data in synchronization with the input data, and a third step of transferring the internal transfer data outputted at the second step to an internal bus.